This invention relates to a method and an apparatus for moving coiler cans having an elongated (flat) horizontal cross section, to and from a sliver charging station of a fiber processing machine, such as a drawing frame or a carding machine. The sliver, composed of cotton or synthetic fibers or the like is discharged by a rotary coiler disc (coiler head) and deposited in coils. The can is, during the sliver charging (depositing) process, moved back-and-forth. An empty can is introduced into the charging station, for example, from an empty-can storage device, the can is charged with sliver in the charging station and the filled can is removed from the charging station, for example, to a full-can storage device.
In a known process of the above-outlined type, as disclosed, for example, in Published International Application WO 91/18135, an empty-can storage device and a full-can storage device are arranged in series. Between the two storage devices an intermediate space for one can is provided which is coupled perpendicularly to the zone of the charging head of the drafting frame by a can displacing device formed of chains and rollers. In operation, an empty can is moved from the empty-can storage device into the intermediate space and then, by means of the can displacing device, to the zone of the charging head where it is filled with sliver and thereafter it is displaced in the opposite direction on the same can displacing device back into the intermediate space and therefrom into the full-can storage device.
Such a conventional process is time-consuming as concerns the steps of can transport and can exchange. The empty and full cans have to travel from the intermediate space to the charging station, and during such a can transport the filling operation in the charging station has to be interrupted. During the return conveyance of an empty can, the can displacing device for the return conveyance of a full can is blocked; likewise, blockage occurs for an empty can during the return of a full can. In addition, after filling the can in the charging station, the can replacement in the intermediate space occurs with a delay because of the above-noted can conveyance. Before an empty can arrives at the sliver charging station, the can replacement in the intermediate space and the transporting to the charging station have to be completed. Can exchange and transport thus proceed consecutively and therefore waiting periods occur in the charging station. In current high-performance drafting frames having sliver delivery speeds of 1,000 m/min and above, such a high output speed capacity of the drafting frame is significantly underutilized because of the abovenoted necessary waiting periods. It is a further disadvantage of the prior art arrangements that they are structurally complex and expensive since the performance of the described process needs particular structural measures. For example, the drafting frame has to be stopped until an empty can is properly positioned in the charging station. Also, the can replacement device and the intermediate space may be utilized only for a single can at any one time.